NEOPROTEROZOIC MICROFOSSILS FROM NORTHERN JIANGSU AND ANHUI
QIAN Mai ping 1)2)4) , YUAN Xun lai 3) , YAN Yong kui 2)4) and DING Bao liang 2)4) 1) Department of Earth Science, Nanjing University, Nanjing 210093 2) Centre for Stratigraphy and Palaeontology, China Geological Survey,Yichang 443003 3) Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences,Nanjing 210008 4) Nanjing Institute of Geology and Mineral Resources, Nanjing 210016
Abundant microfossils were uncovered in marine Neoproterozoic shales, siltstones, and cherts in northern Jiangsu and Anhui provinces, East China. Microfossils in clastic rocks are extracted by maceration and 14 genera and species are identified. Coccoid and filamental cyanobacterial microfossils are three dimensionally well preserved in cherts and 6 taxa are recognized in petrographic thin sections. Macerated microfossils in the upper and middle parts of the Neoproterozoic Liulaobei Formation mainly are fragments with multilayers or monolayers and sphaeromorphs. They are Laminarites antiquissimus, Leiosphaeridia pelucida, Spumiosa alara , and Aspera topsophosphaera bavlinensis . Only two types, Monilinema quadratucella and Synsphaeridium sp., are collected from the Jiuliqiao, Jiayuan and Zhaowei formations, which are polyhedrical or spherical in shape. Abundant spherical and filamental microfossils are macerated from the clastic rocks of the Shijia, Jin shanzhai and Gouhou formations, including Leiosphae ridia hyperboreica, Trachysphaeridium simplex, Annulum difuminatum, Nucellosphaeridium asperatum, Tophoporata sp., Symplassosphaeridium sp., Macro ptycha uniplicata and Taeniatum simplex . This microfossil assemblage can be compared with those of the Neoproterozoic Jingeryu and Xiamaling formations in Jixian, Tianjin, and Hebei Province. Although the systematic paleontology of the above mentioned microfossils is still under investigation, they could provide us with phytoplanktonic data for understanding the biosphere of the coastal marine environment shortly before the Neoproterozoic glaciations. Well preserved three dimensional microfossils, including filamental and coccoid cyanobacteria, occur in the cherts of the Neoproterozoic Niyuan and Jiudingshan formations in northern Anhui and Jiangsu provinces. They are Siphonophycus sp., Eoentophysalis belcherensis, Eozygion grande, Tetraphycus conjionceum, Globophycus rugosum , and Caryosphae roides pristine . This cyanobacteria assemblage was probably benthic, and occurred in nonstromatolitic carbonate depositional environment.
【Fund】： 科技部国家重点基础研究 ( G2 0 0 0 0 7770 1);; 基础工作专项资金 ( 2 0 0 1DEB2 0 0 56 );; 中科院南京地质古生物研究所开放实验室基金 ( 0 13118);; 中国地质调查局综合研究项目 ( 2 0 0 1130 0 0 0 53和 2 0 0 11390 0 0 0 72 )共同资助
【CateGory Index】： Q913
【CateGory Index】： Q913